In a traditional knee arthroplasty surgery, the diseased bone and/or cartilage of a patient is removed and replaced with a prosthetic implant. A surgeon typically prepares the bone using a hand-held oscillating saw blade or other cutting instrument guided by a resection guide or the like, which results in a series of planar bone surface resections. Additionally, the surgeon may use a drill, broach, tamp or other instrument to make holes, slots, depressions or the like in the bone. The planar bone resections and cylindrical bone holes are oriented to interface with flat surfaces and pegs and/or keels formed on a bone engaging surface of a prosthetic implant. An opposite side of the implant includes an articulation surface that is preferably designed to articulate with a like articulation surface formed on an implant to be implanted on the other bone of the knee.
Although implants designed to be implanted on planar cut surfaces of bones have been more widely utilized, implants meant to be implanted on non-planar surfaces have been designed and utilized in surgical procedures. The preparation methods for such implants are often very different than for the above-discussed traditional implants. For instance, milling devices are often utilized to prepare the bone surface to receive the implant. Again, these implants may employ pegs and/or keels to aid in the fixation of implant to the bone. Additionally, like in the traditional planar cut implants, cement or another fixation compound may be utilized to guarantee a solid connection between the implants and the bone.
One drawback in utilizing cements or the like is that the required cement layer often results in an unwanted transformation from a very precisely prepared surface to an imprecise prepared bone surface. This is largely due to the imprecise nature of working with cement. In a situation where a bone surface has been prepared to meet very specific dimensions, application of cement prior to implanting the implant will result in the surface exhibiting less than precise dimensions.
Therefore, there exists a need for implants that do not require the use of cement or the like, but yet remain attached to the bone after implantation.